Release of CFC-11 from disposal of polyurethane foam waste

The halocarbon CFC-11 has extensively been used as a blowing agent for poly urethane (PUR) insulation foams in home appliances and for residential and industrial construction. Release of CFCs is an important factor in the depl etion of the ozone layer. For CFC-11 the future atmospheric concentrations will mainly depend on the continued release from PUR foams. Little is known about rates and time frames of the CFC release from foams especially after treatment and disposal of foam containing waste products. The CFC release is mainly controlled by slow diffusion out through the PUR. From the litera ture and by reevaluation of an old reported experiment, diffusion coefficie nts in the range of 0.05-1.7.10(-14) m(2) s(-1) were found reflecting diffe rences in foam properties and experimental designs. Laboratory experiments studying the distribution of CFC in the foam and the short-term releases af ter shredding showed that about 40% of the CFC is solubilized in the PUR ph ase, and that up to 10% of the total content will be released within a few weeks if the foam is shredded down to 2-cm sized pieces. For smaller pieces the quick release will be larger. Fifty percent of residual CFC content wi ll be released within 9-300 years from 2-cm pieces based on the range in di ffusion coefficients reported, for larger pieces the initial release is ins ignificant, and the release time frames are much longer than for the shredd ed foam.